Latch mechanism for a rocket launcher



June 26, 1956 M. E. BONNETT LATCH MECHANISM FOR A ROCKET LAUNCHER Filed June 19, 1952 INS UL RTION IN V EN TOR.

25 Mi: ch E11 E El Dru-LE1:

ATTOENE Y5 United States Patent LATCH MECHANISM F OR A ROCKET LAUNCHER Mitchell E. Bennett, Havre de Grace, MIL, ass'ignor to the United States of America asrepresented by the Secretary of the Army Application June 19, 1952, Serial No. 294,526

3 Claims. (Cl. 89 --'1.-7)

.(Granted under Title 35,.U. S. Code (1952), see. 266) The invention described herein may be manufactured andusedby or for the Government for governmental pur poses without the payment to me of any royalty thereon.

This invention relates to rocket launchers particularly of the type for launching electrically ignited rockets. Such rockets usually have an electrically insulated contact band about their tail assembly which engages an insulated contact on the launcher tube when and only when, the rocket. is in firing position in the tube. The firing circuit then extends from a source of. voltage, through firing and safety switches'etc., to the insulated band and thence to the ignition squib of the rockets propelling charge. Various safety considerations and sequences are in vol'ved' in the procedure necessary to launch such rockets. The rocket must be first loaded into predetermined position longitudinally within the launcher tube so that means are desirable positively to stop its movement when and only when such position is attained. The positive stop means should be retractible and, the firing circuit should remain open until such stop means is fully withdrawn from the path of the rocket after initiation of its propelling charge. that the circuit again be opened immediately after firing and the stop means returned to operative position.

It is the chief object of this invention to provide a latch mechanism for a rocket launcher which will efiect the foregoingfunctions in a positive and reliable manner and which is, at the same time inexpensive and relatively simple to construct, assemble and apply.

, It" is a further object to provide a. launcher which may be; incorporated as a part of a standardized launcher or maybe embodied as an attachment for existing launchers.

A still: further object is to provide a latch mechanism, as aforesaid, which can be adapted to all calibers of launcher tubes and attached with a minimum of machine work uponthe tube itself.

Other objects and advantages will occur to those skilled in the art after a-- study of the following description in connection with the accompanying. drawing.

in the drawing: v

Figure 1 is a side elevation, partly in section, of the breech end of a 3.5 launcher with my invention incorporated therein and with a rocket loaded therein read for firing.

Figure 2 is an elevation of the breech end of the launcher with the parts in loading position.

7 Figure 31 is a sectional. view taken in av by the line 33. of Figure 1=.

Figure 4 is a detail sectional view taken in a plane identified by line 4-4 of Figure 2.

Referring in detail to the drawing, the numeral 1 identifies a launcher tube for a 3.5" rocket and having the conventional shroud 2 secured to and about its breech end. A mounting clamp 3 encircles the breech end of the tube and is shown in the form of two semicylindrical halves, hinged together at 4 and fixed about the tube by screws 5. The upper half of clamp 3 has a Furthermore, it is highly desirable plane identified A 2,751,818 Patented June 26, 19 56 rearward projection 3a extending along the tube, to provide a mount or support for the blast vane 6, safety switch 7 and stop pin 8. As will be noted from Figure 1, projection 311 has its rearward end upwardly and rearwardly offset to extend over the attaching band portion 2a of the shroud. Projection So has a pair of laterally spaced lugs 9 upstanding therefrom to pivotally support blast vane 6 between them, by pivot 10;

As is clear from inspection of Figure l, the operating end of vane 6 projects through an opening 11 in shroud 2' and is pivotable from one extreme position, shown in dotted lines, Figure 1, wherein the vane is substantially vertical with its operating end positioned to be engaged by the blast, to a second extreme or substantially horizontal position wherein the operating end is practically outside of the shroud.

A bracket 12 has a base portion 12a secured, asby welding, to the upper half of clamp 3. A lug 13 is secured in upstanding relation to base 12a and has a transverse bore receiving a pivot pin 14 Whose protruding ends pivotally support links 15. The other end of these links are pivoted by a pin 16 to the forward end of a lift bar 17, whose rearward end is forked and pivotally connected at 18 to the end of blast vane 6. An operating knob 17a is conveniently provided on the forward end of the bar. The mounting is, in efiect, a parallelogram one, wherein rod 17 moves parallel with itself between the extreme positions indicated in solid and dotted lines upon Figure 1. It will be noted that when moved to the dotted-line position the rod is at greater distance from the launcher tube than in the solid line position.

In addition to lugs 9, projection 3a has fixed thereto, as by welding, a pair of columns or standards 19. The upper end of these standards support the rearward end of bracket 12, including a generally horizontal longitudinal member 12b. A second longitudinal member20 has turned down ends which are bolted or otherwise secured to the longitudinally spaced uprights of bracket 12 to complete the frame. Micro-switch 7 is secured to longitudinal 12b by a hollow threaded stud 7a thereof which extends through a hole in the longitudinal and is secured in position by nuts onthe stud. Operating plunger 22 of the switch extends downwardly through the stud in posit-ion to be engaged and operated by bar 17 as the latter moves upwardly into its final limiting position shown in dotted lines, Figure 1. It will be understood that theplunger 20 isspring urged downwardly and is so constructed that its contacts are closed when moved upwardly by lift bar- 17 during the final portion of its movement. I

Stop pin 8 is mounted for vertical translation within aligned holes in members 12a, 12b, 20, clamp member 3'and launcher tube 1. The pin has a central longitudinal slot 23 which receives bar 17 with a sliding fit and'is so positioned that the upper end of the slot 3' is engaged by the bar whenthe latter moves upwardly. A collar 24 is secured to and about the central portion of pin 8 and acts as a stop limiting the downward movement of the pin to the full-line or loading position shown upon Figure 1. The collar also serves as an abutment for one end of a coil spring 25, the other end of which contacts member 20. As the spring is: under tension, itacts to continuously urge the stop' pindownwardly;v However, due to the fact that slot 23 is of greater vertical dimension than the corresponding dimension of the bar 17, the pin may be moved upwardly independently of the bar.

The lower end of pin 8 is conical and when in lower or loading position, projects a substantial distance into the launcher tube to contact the forward rim or edge of the rocket tail assembly as at 26, Figure 1, whereby the rocket is properly positioned for launching longitudinally within the launcher. This position is one such that a contact button 27, slidably mounted within a dielectric insert 28 in the launcher tube wall, may engage metallic contact ring 29 of the rocket fin or tail assembly. It will be understood that this ring is insulated from the rocket fins and has a lead, not shown, extending within the rocket to the firing squib of its propelling charge.

' Button 27 is urged inwardly toward rocket-contact position, by a leaf spring 30 having its free end secured to the button as by means of a pin 31. The other end of the spring is fixed to the launcher tube by means of screws 32, and insulated therefrom in the usual way, by dielectric blocks 33. A lead 34 connects the spring with one terminal of switch 7 while a second lead 35 extends from the other terminal of the switch to a firing switch and battery, neither being shown.

Figures 2 and 4 shows a possible addition or modification of a latch 36 carried at one end of a leaf spring 37 secured externally of the launcher tube, as at 38. The latch projects through a hole 39 in the tube and is so shaped and positioned as to be cammed outwardly by the rocket R as it is rammed into the launcher, and to snap over the rear edge of ring 29 as the'rocket moves into correct firing position with its edge or point 26 against pin 8. Thereby the rocket is held against rearward or retrograde movement.

The firing circuit extends from one terminal of the battery to a manually-controlled firing switch (not shown) and thence by lead 35 to micro-switch 7, thence by lead 34 to contact spring 30, button 27 and ring 29. Ring 29 is connected by a connection, not shown with a firing squib for the rockets propelling charge and the remaining terminal of the squib is grounded through the rockets case and the launcher tube. If a positive return to the battery is desired spring 37 may be insulated from the launcher tube and used for this purpose. Figure 1 shows the loading position in solid lines wherein vane 6 is retracted and bar 17 in its lowermost position wherein it is clear of the plunger of switch 7, the contacts of which are then open thus placing the launcher in safe condition. At this time, also, the bar 17 has fully released stop pin 8 so that the latter is in its lowermost position with its lower end projecting into the launcher tube and collar 24 in contact with longitudinal 12b, all under the urge of spring 25.

A rocket may now be loaded into the tube during which movement its ogival nose cams pin 8 upwardly against the urge of spring 25. As the rocket body clears the pin, the latter again moves downwardly. Firing position is attained when the tail assembly engages the pin at 26, at which time, latch 36 snaps behind ring 29 and retains the rocket against retrograde movement. Button 27 is now in contact with ring 29. Bar 17 is now raised by rearwardly-directed pressure upon 17a and, as a result, pin 8 is lifted to clear the inner periphery of tube 1, without, however, clearing the clamp and bracket, so that the opening for the pin remains closed. Simultaneously, blast vane 6 is lowered into dotted line position. The final movement of the bar into raised position raises and holds plunger 22 of the switch in contactclosing position. It will be noted that, in the fully raised position of bar 17, links are slightly offset rearwardly from the vertical so that the thrust of spring acts to hold the bar raised with knob 17a against bracket 12 to act as a stop.

The main or firing switch isnow closed to complete the circuit and ignite the propelling charge. The resulting blast drives vane 6 rearwardly to the full-line position of Figure 2, lowers bar 17, opens switch 7 and permits pin 8 to move downwardly under the urge of spring 25. The parts are thus restored to loading, safe" positions.

It will thus be seen that I have provided a relatively simple, unitary latch mechanism which is readily adaptable to various types and calibers of rocket launchers with a minimum of simple machine work. The latch mechanism is simple, reliable and inexpensive to produce and apply.

While I have shown the form of the invention presently preferred by me, various changes, rearrangements and modifications are possible and will occur to those skilled in the art after a perusal of the foregoing disclosure. Hence I desire that the disclosure be taken in an illustrative rather than a limiting sense; and it is my desire and intention to reserve all modifications within the scope of the subjoined claims.

Having thus fully disclosed the invention, what I claim and desire to secure by Letters Patent is:

1. In a rocket launcher for an electrically fired rocket having a firing contact thereon and a forwardly-facing stop surface, a launcher tube, a frame secured to the breech end of said tube, a stop pin axially slidable in said frame radially of said tube, from a first position with one end projecting into said tube in the path of the stop surface of the rocket to a second position free and clear of said path, spring means urging said stop pin into first position, a lift bar, parallelogram link means mounting said bar on said frame substantially parallel with the axis of said tube, said link means including a vane pivotable from a first position clear of the exhaust blast from a rocket in said tube to a second position to be impinged by said blast and moved thereby to first position, a connection moving said pin from first to second position by and in response to actuation of said bar to pivot said vane to second position, a switch carried by said frame in position to be closed by and in response to the final movement of said bar in moving said pin to second position, a contact carried by said tube in position to engage the firing contact of the rocket when its stop surface engages said pin in first position, and a circuit including said contact and switch in series.

2. The rocket launcher of claim 1, said vane when in second position, preventing the loading of a rocket into said tube.

3. The rocket launcher of claim 1, wherein the rocket also has a rearwardly-facing stop surface, and a spring pressed latch on said tube in position to snap behind said rearwardly-facing stop surface as said forwardlyfacing stop surface engages said pin, whereby the rocket is held against retrograde movement.

References Cited in the file of this patent UNITED STATES PATENTS 2,440,723 MacDonald May 4, 1948 2,451,522 Uhl et al Oct. 19, 1948 2,460,929 Goff Feb. 8, 1949 2,496,316 Skinner et al Feb. 7, 1950 2,557,151 Skinner et al. June 19, 1951 2,685,232 Brandt Aug. 3, 1954 FOREIGN PATENTS 496,744 Belgium July 31, 1950 671,873 Great Britain May 14, 1952 

